Avaliação de métodos de medição de altura em florestas naturais

Abstract

The objective of this work was to compare methods of tree height measure in natural foress. Total heights measured by hypsometer Vertex were compared with those obtained by escalade of the trees. The method of visual estimate was also tested, with and without training, as a more practical alternative and of slower cost. The tested methods were evaluated for three height classes: 1 - (15-25 meters); 2 - (25-35 meters) and; 3 - (> 35 meters). At the end, it was concluded that the increase in the height of the trees reduced precision of the estimate for the appraised methods, being more evident in the visual estimate without training. The only statistical difference, at the level of 5% of probability for the test t, among the averages of heights for the appraised methods and the averages of the heights obtained by escalade, in the different classes, occurred in the visual estimate with training in the class 2. The statistics Average Deviation (DM), Average of the Absolute Differences (MD) and Standard Deviation of the Differences (DPD) indicated larger precision in the estimate of the height for the visual estimate with training, following Vertex and visual estimate without training.